"The Great Pyramid of Giza may be a Wonder of the Ancient World, but it's not perfect: Its base is a little lopsided because its builders made a teensy mistake when constructing it, new research reveals. ..."

"... The discovery came as researchers from the US-based Glen Dash Research Foundation and the Ancient Egypt Research Associates (AERA) were studying the magnificent structure to better understand its original dimensions.

Way back when the pyramids were constructed 4,500 years ago, under the rule of Pharaoh Khufu, they were encased in white limestone. Over the years, this limestone outer shell was stripped away - likely for other building projects - leaving the structure we know today.

"Most of those casing stones were removed centuries ago for building material, leaving the pyramid as we see it today, without most of its original shell," Glen Dash, head of the Glen Dash Research Foundation, said in a recent survey report.

To understand what the Great Pyramid was like before this outer shell vanished, the teams set out to take measurements - a task that's much easier said than done. ..."